The present invention relates to an apparatus and method for raising lobsters or other crustaceans such as shrimps, crabs, crayfish and the like and is particularly directed to the crustaceous cannibalistic variety.
In the natural growing habitat of crustaceans such as lobsters adjacent Maine and Nova Scotia, seven to ten years may be required for a lobster to reach a marketable weight of one pound. In such a natural habitat, the growth rate of a lobster is slow and uncertain because the surrounding ocean environment causes a relatively high mortality rate. It has, therefore, been contemplated to raise lobsters under controlled aquaculture systems in which the growing period of a lobster may be substantially reduced by carefully regulating the environmental conditions of the lobsters as by regulating water temperature, avoiding water pollution, assuring proper salt content of the water, and providing a selected optimum diet and care of the lobsters during the post-larval stage. By such careful control of the environment of post-larval lobsters, it is believed possible to raise a one pound lobster in a period of from 21 to 30 months. In addition, it is contemplated that there may be a new market for lobsters of quarter pound size similar to that of baby shrimp.
It will also be readily apparent that to commercially raise the many thousands of lobsters required to satisfy the demand therefor, an efficient, effective means for feeding a large number of lobsters must be provided. The physical arrangement of daily feeding a large number of lobsters held in individual, separate cells presents numerous problems since uneaten food must be timely disposed of before spoiling and endangering the health of the lobsters and the manner of transporting and presenting the food substances to a large number of individual cells must be accomplished in a foolproof, efficient and effective manner. Since the raising of lobsters requires feeding at least once every 24 hours, the arrangement for feeding lobsters becomes extremely important. Thus feeding and caring for thousands of lobsters, each in an individual cell, presents a number of problems.
Prior proposed apparatuses and methods for aquaculture of cannibalistic varieties have included separate habitats for each of the crustaceans by providing a clear, transparent, rigid plastic tube in which a number of discs or shelves of plastic material are arranged in vertical spaced relation to form a plurality of vertically disposed separate chambers, each chamber to contain a baby lobster. Feeding of the lobsters in separate chambers included use of a vertical feed rod having small notches therealong to retain small elements of food, the feed rod being adapted to be lowered into each of the chambers for making the food accessible to the lobsters. Thus one feed rod may supply food to 10 to 20 cells (see U.S. Pat. No. 3,815,546).
Another prior proposed aquaculture system is shown in U.S. Pat. No. 3,916,833 in which vertical and horizontal rows of cells are provided for individual raising of lobsters, the walls of the cells being perforated for circulation of water and the floor of lobsters in each cell comprising a wire mesh which permitted the feeding of each cell by allowing the food to descend through water by gravity and to be caught on a small tray in each cell, the tray of each cell being horizontally offset from the tray thereabove. Mass gravity feeding of a plurality of cells in this manner was haphazard--the trays may catch different amounts of food.
Another arrangement of cages with cells for individual raising and feeding of separated lobsters is shown in U.S. Pat. No. 3,499,421, the cages being movable between a submerged position in water and an out of the water servicing position. Still other arrangements of aquaculture systems for individual raising of crustaceans, such as lobsters, are described in U.S. Pat. Nos. 4,212,268, 4,300,477, 4,007,709.